The Ivorian was sent off for a headbutt in last weekend’s Premier League clash at Elland Road, but kept his place in the side for the trip to Norway and opened the scoring with a superb finish before Reiss Nelson doubled the lead five minutes later.
Substitute Folarin Balogun then scored his first Arsenal goal within moments of replacing Eddie Nketiah to cap a perfect night for the north Londoners.
The result means the Gunners qualify for the last-32 as Group B winners with two games to spare, meaning Mikel Arteta will have the option of resting players amid the busy fixture list for the remaining group stage matches next month.
This weekend get a £10 free bet with Betfair, when you bet £10 on a Same Game Multi on the Premier League.
Terms: Min £10 Same Game Multi bet on any EPL match this Fri – Sun. Free bet valid for 72 hours, awarded at bet settlement. Excludes cashed out bets. T&Cs apply.